Leveraging Social Media and AI to foster Secure Societies against Online and Offline Threats

My thesis aims to exploit social media data and Artificial Intelligence (AI) techniques to combat possible online and offline threats. It therefore provides contributions in two directions: (i) uncovering and characterizing possible threats affecting ecosystems online and (ii) anchoring online information to events taking place offline, to improve our crisis response capacity. In both cases, on the one hand we help improve AI techniques, which enable essential applications; on the other, we design and apply global approaches to address specific threats.